The present invention relates to an axle support for a vehicle, in particular for a vehicle having an electric drive. With respect to the prior art, reference is made by way of example to EP1253028 and, in particular, to DE102012005561.
FIG. 1 shows (with the exception of the parts having the designations 12 and 14) a conventional axle support. The conventional axle support has two longitudinal carriers 2, 3, to which in each case one wheel suspension system 4 is fastened. The two longitudinal carriers 2, 3 are connected to one another via crossmembers 107, 108. A holding device 9 extends parallel to the crossmembers 107, 108, on which holding device 9 a constituent part 10 of an axle regulating system (here, an actuator of a rear axle steering system) is fastened.
It is known, furthermore, that vehicle axle supports are of hollow or shell-shaped construction, inter alia, for saving material and therefore vehicle weight or for reasons of optimized stiffness and strength.
For instance, DE102012005561A1 which is mentioned above, describes a subframe in a vehicle. The subframe has in each case two crossmembers and longitudinal carriers. Here, two crossmembers which are constructed by way of, in each case, two shell elements are illustrated, which crossmembers in each case have a hollow construction as a result of the connection of the two shell elements. Inter alia, improvements in the stiffness and strength properties of the subframe are to be achieved by way of a hollow or shell-shaped construction of this type of the crossmembers.
Furthermore, EP1253028 describes a vehicle axle support or a link of a motor vehicle suspension system, which vehicle axle support or link has a free interior space, that is to say a cavity, in its cross section at least in sections. This cavity is utilized to accommodate hydraulic lines in a protected manner. It can be avoided here that the lines are damaged by environmental effects, such as by stone chipping.
In addition to the protection of vehicle components and an optimum design of vehicle parts with regard to stiffness and strength requirements, an optimum installation space design plays a role which is becoming more and more important. As the number of vehicle constituent parts rises as a result of added electronics or the like, the complexity of the vehicle components and their accommodation in the vehicle itself likewise increases. Thus, for example, the conventional axle supports which are illustrated in the prior art leave a relatively small amount of installation space free for the integration of added vehicle constituent parts, such as an electric drive, into the axle support.
It is an object of the present invention to provide an axle support which ensures both an improvement with regard to stiffness and strength requirements and an optimum utilization of installation space in the vehicle, by way of a structure of hollow configuration.
This and other objects are achieved by an axle support for a vehicle. The vehicle is, in particular, a two-track motor vehicle. The axle support is particularly preferably used in conjunction with an electrically driven vehicle. The axle support has a left-hand longitudinal carrier for fastening a left-hand wheel suspension system, and a right-hand longitudinal carrier for fastening a right-hand wheel suspension system. Furthermore, at least one cross member which connects the two longitudinal carriers is provided for transmitting chassis loads. It is provided within the context of the invention that the cross member is formed by way of two shells which are placed onto one another. The two shells are connected to one another such that they can be released without destruction. A cavity remains between the two shells of the cross member, which cavity can be utilized for further constituent parts of the vehicle, in particular for constituent parts of an axle steering system. This results overall in a design of the axle support which is optimized in terms of installation space. On account of the connection between the two shells which can be released without destruction, both simple initial assembly and later maintenance of the constituent parts of an axle steering system which are situated in the cavity are possible. Here, “can be released without destruction” is to be understood to mean, in particular, every connection which is not integrally joined. The two shells are therefore not connected to one another, in particular, by way of welding, brazing or adhesive bonding. A riveted connection is possible here, since said riveted connection can be released merely by way of destruction of the rivet, the two shells remaining completely un-destroyed in the process. In particular, a screw connection between the two shells will be selected here. One of the two shells can also be of flat configuration and therefore have the shape of a cover. It is merely decisive that a cavity which can be utilized remains on account of the construction of the cross member according to the invention.
The axle support particularly preferably includes at least one constituent part of an axle steering system. Specifically, the constituent part is installed according to the invention in the cavity between the two shells. The axle steering system is particularly preferably a rear axle steering system. Here, the constituent part which is integrated into the cavity is particularly preferably an electric, pneumatic or hydraulic actuator of the axle steering system which, as is customary, is configured as an Ackerman steering system. The actuator is advantageously connected via a corresponding linkage to the wheel suspension system, more precisely to its wheel support.
In addition to constituent parts of an axle steering system, an electronic power system can also be accommodated in the cavity, for example.
The axle support advantageously includes a holding device which is connected on both sides to the longitudinal carriers. The holding device extends through the cavity between the two shells of the cross member. The constituent part of the axle steering system is advantageously fastened to the holding device. Direct fastening of the constituent part of the axle steering system to the shells therefore does not take place, with the result that assembly and dismantling are facilitated here.
It is preferably provided that one of the two shells is fixedly connected directly to the two longitudinal carriers. As an alternative, the two shells can also be connected by way of their respective ends directly to the two longitudinal carriers. This results in a very stiff structure.
The cross member has an overall length. The overall length corresponds substantially to the spacing of the two longitudinal carriers. Each of the two shells preferably extends over at least 80%, preferably 100%, of the overall length. Here, at least one of the two shells has to extend over 100% of the overall length.
It is preferably provided, furthermore, that no wheel control components, for example links, are fastened to one of the two shells, preferably to the lower shell. This achieves a situation where the tolerance effects with regard to the axle support-side attachment points of the wheel control components are reduced to a magnitude which is known in the prior art. Furthermore, this results in decisive advantages during the assembly and dismantling. Even before the second shell is attached, all the wheel control components can be fastened to the construction comprising the two longitudinal carriers and the at least one shell of the at least one cross member. During servicing, merely the lower shell can be dismantled, without it being necessary here to dismantle wheel control components. Very simple and rapid access to the component in the cavity is possible as a result.
The axle support advantageously includes a further cross member and a plate-shaped shear area. The plate-shaped shear area is connected to the two cross members, it being provided that the shear area is connected to the further cross member such that it can be released without destruction. On the side of the two-shell cross member, the shear area is connected merely to one of the two shells. This shell therefore forms a unit together with the shear area, which unit can be dismantled, for example by way of bolts being released.
The axle support advantageously includes an electric machine for driving the vehicle. The electric machine is arranged between the two longitudinal carriers. If two cross members are used, the electric machine is advantageously arranged between the two cross members. Simple access to the electric machine is always possible from below by way of the one shell with the shear area being dismantled.
Moreover, the two-shell construction of the cross member makes the use of different materials possible. It is provided, in particular, that the lower shell which is connected to the shear area is manufactured from fiber reinforced plastic.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.